// ESET 462 Project Code
// Backyard Light System

// Defining Variables
int photocellPin = 0;     // the ldr and 10K pulldown are connected to a0 (voltage divider)
int photocellReading;     // the analog reading from the sensor at vd
int LEDpin = 11;          // connect LED chip to pin 11 (PWM pin)
int LEDbrightness;        // brightness of the LED chip

int sensor = 2;              // output pin of pir sensor
int state = LOW;             // no motion detected by default
int sensor_status = 0;       // stores status of pir sensor


void setup(void) {
  pinMode(sensor, INPUT);    // initialize sensor as input
  Serial.begin(9600); // Send debugging info via the Serial monitor
}
 
void loop(void) {
  // ******* LED Chip ******* //
  photocellReading = analogRead(photocellPin);  

  // LED gets brighter the darker it is at sensor
  // inverts the reading from 0-1023 back to 1023-0
  photocellReading = 1023 - photocellReading;

  //--------------------------------------------------------

  sensor_status = digitalRead(sensor);   // pir sensor value

  if (sensor_status == HIGH){   // if sensor detects motion

    if (state == LOW) {
      Serial.println("Motion detected!"); 
      state = HIGH;       // update variable state to HIGH
    }

    // While condition for when sensor detects motion
    while(sensor_status == HIGH){ 
      photocellReading = analogRead(photocellPin); 
      photocellReading = 1023 - photocellReading;
        
      //Powers LED based on available natural light
      LEDbrightness = map(photocellReading, 0, 1023, 0, 255);//maps 0-1023 to 0-255 since thats the range analogWrite uses
      analogWrite(LEDpin, LEDbrightness);
      delay(100);
      sensor_status = digitalRead(sensor);   // pir sensor value
    }

  } 
  else { // if sensor does not detect motion
    if (state == HIGH){
      Serial.println("Motion stopped!");
      state = LOW;       // update variable state to LOW
    }
    
    //Powers off LED
    analogWrite(LEDpin, 0);
    delay(100);
  }

}